I'm happy the op is so casual about these misconceptions and finds them silly, can even name favourites. I've heard of Bitcoin being a financial pyramid (so, #2) from a relative, but it's not the kind of relative who can be convinced by any arguments, really, so I was irritated that he maintained this position.
In general, I like the misconceptions people have about fiat and banks more. Like how many assume fiat is backed up by something that gives it value, or how most think that the money they have in their bank accounts is actually theirs and is actually there.
Or, how people think they need to "build credit" when they are young, and think the way to do this is to get into credit card debt, and pay ridiculous interest rates, and get caught in a cycle of bad debt.